ZIF-67 decorated with silica nanoparticles and graphene oxide nanosheets composite modified electrode for simultaneous determination of paracetamol and diclofenac.

In this work, a novel nanocomposite containing zeolitic imidazolate framework-67 decorated silica nanoparticles/graphene oxide nanosheets (ZIF-67/SiONPs/GONs) was synthesized and used for the fabrication of the modified glassy carbon electrode for individual and simultaneous electrodetermination of paracetamol (PAR) and diclofenac (DIC) at trace levels. Structural and morphological characterization of the nanocomposite were carried out using suitable techniques. The modified electrode; ZIF-67/SiONPs/GONs/GCE, exhibited excellent electrocatalytic activities toward the oxidation of PAR and DIC than the bare GCE, GONs/GCE, SiONPs/GONs/GCE and ZIF-67/GCE. Through using differential pulse voltammetry, the individual and simultaneous determination of PAR and DIC were conducted by the ZIF-67/SiONPs/GONs/GCE. Under optimal conditions, it has been observed that the calibration plots for PAR and DIC exhibit linearity within the concentration ranges of 0.5-190 (PAR) and 0.5-200 µM (DIC), with detection limits of 0.29 and 0.132 µM for PAR and DIC, respectively. The ZIF-67/SiONPs/GONs/GCE shows commendable stability, reproducibility, and repeatability, and the proposed method is evaluated by individual and simultaneous determination of PAR and DIC in real samples with satisfactory results (recovery > 97%).